1. Field
The embodiments relate to a method of manufacturing a semiconductor device, and more particularly, to a method and apparatus for cleaning a photomask.
2. Description of the Related Art
A photolithography process may be used to form a predetermined pattern on a semiconductor substrate. In particular, a photoresist pattern may be formed by transcribing a pattern of a photomask onto a photoresist layer of a semiconductor substrate, and a predetermined pattern may be formed by etching a semiconductor substrate or a material layer formed thereon by using the photoresist pattern.
The photomask may be used to form the photoresist pattern on the semiconductor substrate. For example, the photomask may be formed by making a shielding pattern made of a material such as chromium (Cr) on a transparent substrate, e.g., quartz. Then, a shielding pattern image is transcribed onto the photoresist layer of the semiconductor substrate by exposing the photomask on which the shielding pattern is formed.
However, when foreign substances exist on the photomask, the shielding pattern image may not be effectively transcribed onto the photoresist layer. In addition, when the exposing of the photomask is continually performed, haze or a critical dimension skew may occur on the photomask. Thus, during a manufacturing process of a semiconductor device, the photomask has to be periodically cleaned. The cleaning operation of the photomask may include removing a photoresist, removing foreign substances/particles/contamination substances, removing remnant pellicle adhesives, and/or the like.